The most basic principle of a three-dimensional display technology is that left and right eyes of a person receive different pictures, and then image information is superposed and regenerated in a brain, thus generating a three-dimensional effect.
The three-dimensional display technology is mainly divided into a naked-eye type and a glasses type, a structure of a commonly-used naked-eye type three-dimensional display device is that a three-dimensional grating is added on a display screen, and the three-dimensional grating is divided into a lenticular lens grating and a slit grating (parallax barrier) in terms of implementation manner, both of which can be realized by using a liquid crystal grating. For example, the liquid crystal grating as shown in FIG. 1 generally comprises: an upper polarizer 1, a lower polarizer 2, an upper substrate 3, a lower substrate 4 and a liquid crystal layer 5 between the two substrates, wherein the lower substrate 4 and the upper substrate 3 are respectively provided with a plate-shaped electrode 7 and strip electrodes 6.
Exemplarily, a working principle of the liquid crystal grating as the parallax barrier is as follows:
When a potential difference between the strip electrodes 6 and the plate-shaped electrode 7 generates an electric field, liquid crystal molecules corresponding to the strip electrodes 6 rotate while other liquid crystal molecules keep their original orientation without rotation. At the moment, light enters from the lower polarizer 2, polarized light parallel with a transmission axis of the lower polarizer 2 enters the liquid crystal layer 5, the polarized light is gradually changed in vibration direction when passing through the rotated liquid crystal molecules, when reaching the upper polarizer 1, the vibration direction of the polarized light and a transmission axis of the upper polarizer 1 are inconsistent, then light cannot pass through, so light-shielding dark stripes are formed in regions corresponding to the strip electrodes 6; after the polarized light passes through the liquid crystal molecules which do not rotate, the vibration direction thereof is not changed, and the vibration direction of the polarized light reaching the upper polarizer 1 and the transmission axis of the upper polarizer 1 are consistent, then light can pass through, so light-transmitting bright stripes are formed in regions not corresponding to the strip electrodes, and the slit grating with alternately dark and bright stripes is formed, so as to form a grating type three-dimensional display mode. In the three-dimensional display mode, the slit grating enables light emitted from left-eye pixels to only enter the left eye, and light emitted from right-eye pixels to only enter the right eye, and a three-dimensional display effect is realized by separating left-eye and right-eye images.
At present, along with development of a touch technology, a 3D display device integrated with a touch function and a three-dimensional display function appears, and this requires to add a layer of touch panel on the three-dimensional grating; as such a structure and a production process thereof are relatively complex and require the relatively high alignment precision during adhering, the manufacturing cost of the whole assembly may be increased, and a thickness of the display device may be greatly increased as the touch panel is additionally added.